The invention relates generally to thermal management of electronics enclosures. More particularly, the invention relates to a reconfigurable apparatus for thermal management of horizontal enclosures.
Electronic equipment can generate significant heat during operation. The performance of the equipment is typically affected by temperature. Performance may become unreliable if the electronics are subject to high temperatures or large temperature variations. The thermal management of electronic enclosures is becoming increasingly challenging as the power density of the electronics increases. For example, a common form factor for communications equipment enclosures is the horizontal box or xe2x80x9cpizza boxxe2x80x9d. Such enclosures are particularly challenging because the only accessible surfaces for air cooling are the front and rear panels. For some applications, only the front panel is useful for air cooling due to the mounting of the enclosure relative to other enclosures or adjacent walls. Moreover, the enclosure size must be maintained to preserve the number of enclosures that can be deployed in a fixed space. The thermal management of these enclosures has to be effective, affordable and reliable.
Generally, cooling is achieved by providing airflow across the electronics to remove excess heat. The airflow can introduce dust and other contaminants into the electronics environment, potentially leading to failure of the electronic components. Air filters are sometimes used to limit the dust and particulates, however, the power, size and cost of the fans are generally increased to maintain the cooling efficiency. Moreover, air filters require periodic cleaning or replacement.
Accordingly, there exists a need for a thermal management apparatus that meets the requirements described above. The present invention satisfies these needs and provides additional advantages.
In one aspect, the invention features an apparatus for thermal management of an electronics module. The apparatus includes a first fan to generate an inlet airflow and an exhaust airflow along a first fan axis, and a second fan to generate an inlet airflow and an exhaust airflow along a second fan axis. A flow director is disposed on the first fan axis to redirect the exhaust airflow of the first fan to the second fan along the second fan axis. The apparatus also includes a heat sink having a first portion disposed in one or both of the exhaust airflow of the first fan and the inlet airflow of the second fan. The heat sink also has a second portion that can be thermally coupled with the electronics module. The apparatus also includes an enclosure surrounding the heat sink and the electronics module. The heat sink and the enclosure define a first volume and a second volume. The first volume includes the exhaust airflow of the first fan and the inlet airflow of the second fan. The second volume includes the electronics module and is isolated from the airflows generated by the first and second fans.
In one embodiment the apparatus also includes a first louver disposed in the inlet airflow of the first fan and a second louver disposed in the exhaust airflow of the second fan. The first louver is configured at a first angle with respect to the first and second fan axes and the second louver is configured at a second angle with respect to the first and second fan axes that is opposite the first angle. The inlet airflow of the first fan and the exhaust airflow of the second fan are thereby spatially separate.
In another aspect, the invention features a reconfigurable apparatus for thermal management of an electronics module. The reconfigurable apparatus includes a first fan and a second fan generating an airflow along a first fan axis and a second axis, respectively. The second fan axis is substantially parallel to the first fan axis. The airflow from the second fan is in the same direction as the airflow from the first fan when the reconfigurable apparatus is in a first configuration. The airflow from the second fan is in an opposite direction to the airflow from the first fan when the reconfigurable apparatus is in a second configuration. The reconfigurable apparatus also includes a removable flow deflector disposed on the first fan axis when the reconfigurable apparatus is in the second configuration. The removable flow director directs the airflow of the first fan to the second fan along the second fan axis. The reconfigurable apparatus also includes a heat sink having a first portion disposed in one or both of the airflow of the first fan and the airflow of the second fan. The heat sink has a second portion that can be thermally coupled to the electronics module.
In one embodiment the reconfigurable apparatus also includes an enclosure surrounding the heat sink and the electronics module. The heat sink and the enclosure define a first volume and a second volume. The first volume includes the airflows generated by the first and second fans and the second volume includes the electronics module. In another embodiment the heat sink includes a thermal spreader plate that separates the first volume and the second volume. In yet another embodiment the reconfigurable apparatus includes a first louver and a second louver. The first louver is disposed on the first fan axis and is configured at a first angle with respect to the first and second fan axes. The second louver is disposed on the second fan axis and is configured at a second angle with respect to the first and second fan axes that is opposite the first angle so that an airflow exhausted through the second louver does not interfere with the airflow received at the first louver.